If you’re looking for CBD oil products, there’s a good chance you can find a store selling some version in just about any direction you travel. The use of cannabis as medicine (CaM) both prescribed and non-prescribed has increased markedly in the last decade, mirrored in a global shift in cannabis policy towards a more permissive stance. There is some evidence that cannabis functions as a substitute for prescription drugs, particularly opioids; however, more knowledge is needed on the motives of substitution users, their patterns of use, and perceived effects of substitution use. To explore who substitutes prescription drugs with cannabis, the type of prescription drugs substituted and the type of cannabis used, and the impact that substitution with cannabis has on prescription drug use as well as the motives for substitution in terms of experienced effects and side effects. A self-selected convenience sample was recruited through social media, public media, and patient organizations to take part in an anonymous online survey. Inclusion criteria were 18 years or older and use of cannabis (prescribed or non-prescribed) with a medical purpose. The final sample included 2.841 respondents of which the majority (91%) used non-prescribed cannabis, and more than half (54.6%) had used CaM with the purpose of replacing a prescribed drug. Compared to non-substitution users, substitution users were more likely to be women and to use CaM in the treatment of chronic pain and other somatic conditions. Pain medication (67.2%), antidepressants (24.5%), and arthritis medication (20.7%) were the most common types of drugs replaced with CaM. Among substitution users, 38.1% reported termination of prescription drug use, and 45.9% a substantial decrease in prescription drug use. The most frequent type of cannabis used as a substitute was CBD-oil (65.2%), followed by ‘hash, pot or skunk’ (36.6%). More than half (65.8%) found CaM much more effective compared to prescription drugs, and 85.5% that the side effects associated with prescription drug use were much worse compared to use of CaM. CaM is frequently used as a substitute for prescription drugs, particularly opioids. More research is needed on the long-term consequences of use of CaM, including the impact from low and high THC cannabis products on specific somatic and mental health conditions. Cannabidiol prescription in clinical practice: an audit on the first 400 patients in New Zealand Cannabidiol (CBD) is the non-euphoriant component of cannabis. In 2017, the New Zealand Misuse of
Dr. Karen Keough on Prescription CBD Oil vs. Over-the-Counter CBD Products
If you’re looking for CBD oil products, there’s a good chance you can find a store selling some version in just about any direction you travel. CBD specialty stores have popped up throughout Austin with at least eight opening in 2018 alone.
The popularity of CBD oil is due to the vast number of suggested promises it can deliver — everything from easing achy joints to insomnia. Proof that it actually helps these issues is limited, however, there is data that shows it can be effective at managing seizures associated with epilepsy. We’ve seen some impressive benefits among children in our own practice since we began prescribing CBD in 2018. Importantly, the CBD oil used for epilepsy differs from over-the-counter and must be prescribed by a doctor — it’s not available over-the-counter.
So what’s the difference between CBD products you can buy off-the-shelf and ones which must be prescribed?
Child Neurology Consultants’ pediatric neurologist Dr. Karen Keough recently made comments in a story for Community Impact about the differences between over-the-counter CBD and prescription. She stresses that the prescription or medicinal CBD is formulated according to scientific research, where others are not.
Dr. Keough is also chief medical officer for Compassionate Cultivation which is one of only three companies in Texas licensed to produce medicinal CBD.
“This is legitimate medicine, and particularly in the world of epilepsy, it can be exceptionally effective for a small group of kids who try it, and it turns out to be extremely safe,” Dr. Keough said.
Some key differences between doctor-prescribed CBD and over-the-counter products include:
- CBD available in stores is produced from hemp which is an industrial crop in the state of Texas that can be legally grown and then widely distributed. The wide range of over-the-counter products have little quality control, and a large study by the Centers for Disease Control (CDC) showed that some of these products actually did not contain any medication at all.
- Medical CBD, only available with a prescription, is derived from cannabis, not hemp. Its use and distribution is limited and heavily regulated via the Texas Compassionate Use Program (TCUP) because the THC content of medicinal CBD is higher than in over-the-counter products. The regulation and oversight of the TCUP means reliable, high-quality medication.
- While the benefits of over-the-counter, hemp-derived CBD products are based on lots of Internet testimonials, larger scale medical studies show the positive benefits of doctor-prescribed CBD oil on epilepsy patients.
Both retailers who sell CBD products and doctors who prescribe it agree though that there needs to be continued funding and research devoted to the medical use of CBD so that patients can know more about how it will affect them.
This year the Texas Legislature passed a bill that expands the TCUP to many other conditions, including other forms of epilepsy, autism, spasticity due to cerebral palsy and others like multiple sclerosis, and additional progressive neurological diseases. These changes will start within the next month, and many more patients will have access to medical CBD through the TCUP.
Exploring the use of cannabis as a substitute for prescription drugs in a convenience sample
The use of cannabis as medicine (CaM) both prescribed and non-prescribed has increased markedly in the last decade, mirrored in a global shift in cannabis policy towards a more permissive stance. There is some evidence that cannabis functions as a substitute for prescription drugs, particularly opioids; however, more knowledge is needed on the motives of substitution users, their patterns of use, and perceived effects of substitution use.
To explore who substitutes prescription drugs with cannabis, the type of prescription drugs substituted and the type of cannabis used, and the impact that substitution with cannabis has on prescription drug use as well as the motives for substitution in terms of experienced effects and side effects.
A self-selected convenience sample was recruited through social media, public media, and patient organizations to take part in an anonymous online survey. Inclusion criteria were 18 years or older and use of cannabis (prescribed or non-prescribed) with a medical purpose.
The final sample included 2.841 respondents of which the majority (91%) used non-prescribed cannabis, and more than half (54.6%) had used CaM with the purpose of replacing a prescribed drug. Compared to non-substitution users, substitution users were more likely to be women and to use CaM in the treatment of chronic pain and other somatic conditions. Pain medication (67.2%), antidepressants (24.5%), and arthritis medication (20.7%) were the most common types of drugs replaced with CaM. Among substitution users, 38.1% reported termination of prescription drug use, and 45.9% a substantial decrease in prescription drug use. The most frequent type of cannabis used as a substitute was CBD-oil (65.2%), followed by ‘hash, pot or skunk’ (36.6%). More than half (65.8%) found CaM much more effective compared to prescription drugs, and 85.5% that the side effects associated with prescription drug use were much worse compared to use of CaM.
CaM is frequently used as a substitute for prescription drugs, particularly opioids. More research is needed on the long-term consequences of use of CaM, including the impact from low and high THC cannabis products on specific somatic and mental health conditions.
In recent years, there has been a global shift in perspectives on the utility of cannabis. While cannabis has predominantly been associated with recreational and/or problematic use, the plant or its components, cannabinoids, are increasingly regarded as a viable treatment option for medical conditions, such as chronic pain, spasticity, nausea, and epilepsy , and as a potential treatment of other conditions [2,3,4].
The medicalization of cannabis is in large part driven by the discovery of the endocannabinoid system in the late eighties, pharmaceutical interests in cannabinoids, and a growth in user demand for access to medical cannabis (cannabis prescribed by a doctor) [5, 6]. This development is mirrored in the rapidly shifting policy on the adoption of medical cannabis laws in more than 30 states in the USA , Australia , Canada  and several European countries , including Denmark . However, the introduction of medical cannabis into medicine is controversial and highly debated. While critics caution use of medical cannabis due to the limited high-quality evidence [12, 13], proponents argue that medical cannabis constitutes an important harm reduction strategy and may function as a qualified substitute for prescription drugs, particularly opioids [14, 15] in the context of the opioid-epidemic in the USA  and Canada .
In drug research, the term “substitution” is conventionally associated with the use of opioid antagonists, such as methadone, in the treatment of opioid addiction [18, 19]. The concept of substitution has its origins in behavioral economics and involves the assessment of the interaction of multiple concurrent commodities . According to this concept, a substance is regarded as a substitute if it acts as a replacement, or leads to reduced use of another substance (e.g., treating heroin addiction with buprenorphine) . Conversely, two substances may be complimentary when the increased consumption of one substance enhances the consumption of the other (e.g., tobacco smoking is often linked to excessive use of alcohol) . Lastly, if there is no interaction on consumption patterns between substances, they are independent (e.g., it has been found that a change in price of alcohol has no impact on consumption of ecstasy ).
Substitution of cannabis for prescription drugs
Emerging research indicates that the increased use of CaM (cannabis as medicine) has had a substitution effect on prescription drug use. In several cross-sectional surveys conducted in the USA and Canada users of CaM report substituting cannabis for prescription drugs, of which opioid, anti-depressive, and anxiolytic drugs are the most prevalent [24,25,26,27,28,29]. In fact, substitution of prescription drugs is the most common motive among users of medical cannabis, surpassing substitution rates for alcohol and illicit drugs [24, 25, 30, 31]. Moreover, state medical cannabis laws in the USA have been associated with a sizeable reduction in prescription drugs , particularly opioid prescriptions [33,34,35], and with fewer prescription opioid-related hospitalizations, lower rates of opioid overdoses, and decreases in opioid-related healthcare costs . A potential substitution effect of CaM on prescription drug use in a European context is much less explored, and findings from the USA in particular, may not be applicable, due to the considerable variations in health care systems [37, 38] and laws on prescription drugs and cannabis. However, a recent Italian study found that an unintended legalization of cannabis products with less than 0.6% Δ-9-tetrahydrocannabinol (THC; main psychoactive component of cannabis) between December 2016 and May 2019  was associated with a considerable decrease in pharmacy sales of anxiolytics, sedatives and anti-psychotics, and a moderate decrease in the sale of opioids, anti-depressants, anti-epileptics, and migraine medication .
When evaluating the harm reduction potential of substituting prescription drugs with CaM, it is relevant to consider the subtype of cannabis used as a substitute. Emerging research shows that potential harms related to consumption of cannabis depend on the composition of active components (cannabinoids) in the cannabis used, as cannabis products with high levels of THC are more harmful in terms of negative impact on cognitive function, anxiety- and psychotic symptoms, and addiction, compared to low THC-products [41,42,43,44,45]. Moreover, other studies indicate that Cannabidiol (CBD; main non-psychoactive component of cannabis) has anxiolytic and antipsychotic effects [43,44,45], and therapeutic effects on addiction, including opioid, stimulant, and cannabis addiction [46, 47]. Further, some evidence suggests that CBD may protect against some of the harmful effects of THC [44, 48]. Taken together, these findings highlight the relevance of the subtype of CaM used in an evaluation of potential harm reduction related to the substitution effect of CaM.
Medical cannabis as the “lesser of two evils?”
In light of recent research findings on the substitution effect of CaM on opioid use, CaM has been suggested as a valuable intervention strategy in combatting the ongoing opioid epidemic in the USA and Canada [14,15,16,17, 49]. The most frequent rationales behind this suggestion are the substantial evidence that cannabis is effective in treating chronic pain in adults , the prevalent use of medical cannabis in pain management , and the fact that, unlike opioids, cannabis has no reported deaths due to overdose , as acute effects of cannabis do not depress respiratory function [52, 53]. The non-psychoactive component of cannabis, CBD, has been of particular interest as a target for opioid use disorder [16, 54], as CBD has a discrete modulatory effect on the endocannabinoid system compared to the direct action of THC, giving CBD a broader therapeutic range . Also, there may be an opioid-sparing effect of cannabis, as pre-clinical studies show that co-administration of cannabinoids with opioids enables a reduction in opioid dose without loss of analgesic efficacy . On the basis of growing indications that cannabis may be a viable tool in targeting the adverse effects of opioid use, some US states have recently modified their medical cannabis laws, allowing patients to substitute their prescribed opioids with medical cannabis . What is interesting about this development is that the medical value of cannabis appears to be based not only on what cannabis is, in terms of the available evidence on its efficacy, but also on what cannabis is not, when compared to opioids [14, 15, 17]. This perception has also been described in a qualitative study of physicians in Israel, where cannabis was presented as a justified treatment option and as a “the lesser of two evils” by emphasizing problems in standard medications . However, opponents of this position argue that the current evidence for the use of medical cannabis is weak, that more clinical trials are needed [58, 59], and that other efficacious medications for the treatment of problematic opioid use are under prescribed . Furthermore, some evidence suggests medical cannabis may not function as a long-term substitute for opioids , and cannabis use is associated with increased risk of problematic opioid use [62, 63]. Still, despite the recommendations to wait for more valid evidence on the long-term effects of substituting prescription drugs with CaM, several studies indicate that many of the current users of CaM are using cannabis as a substitute for prescription drugs, particularly opioids, and report fewer side effects and better symptom management as their motive for substitution [28, 64].
Cannabis as a substitute for prescription drugs in a Danish context
In Denmark, a four year Medical Cannabis Pilot Program (MCPP) was initiated in 2018 with the aim of providing a safe and legal framework for prescribed whole plant cannabis to patients with multiple sclerosis, spinal cord injury, chronic pain, or chemotherapy-related nausea, and vomiting . Medical cannabis is not formally categorized in the MCPP as a potential substitute for any prescribed drug, and the Danish Medicines Agency recommends that only patients who have failed to respond to conventionally approved drugs are prescribed medical cannabis . Thus, in Denmark, medical cannabis is not officially regarded as a tool to combat misuse of prescription drugs, but instead as a last resort. Despite the changes in policy, there are indications of a large use of medicinal (non-prescribed) cannabis occurring outside the legal framework of the MCPP . In the first survey in Denmark on the use of CaM, we recently found that the vast majority of respondents (90.9%) reported use of CaM without a doctor’s prescription . Moreover, we found that most users of CaM reported limited recreational experience (63.9%) and a preference for low potency CBD-oil (65%) . Of note, there are several other indications that cannabis oil has become more prevalent in Denmark in recent years, including a growth in web-shops selling low-potency cannabis oil , an increase in selling of cannabis oil at the illegal open drug scene Christiania , and an increase in police confiscations of cannabis oil . All use of cannabis outside the MCPP is illegal, both sale and possession, except from cannabis products containing less than 0.2% THC. Such products are illegal to sell if they are considered to be medicine by the Danish Medicines Agency, but they are not illegal to possess .
The MCPP has set the legal parameters for the utility of CaM in Denmark, but we lack knowledge on the parameters users of CaM set in practice; do they substitute prescription drugs with CaM, and do they perceive CaM to be the lesser of two evils in terms of experienced effects and side effects? Examining the use of CaM as a substitute for prescription opioids is of particular public health interest, in the context of the increased use of prescription opioids in the Danish health care system, which has undergone recent media scrutiny in Denmark . As a response, the Danish Medicines Agency started an investigation, which showed that use of the “weaker opioid” Tramadol was driving a substantial part of the rise in opioid use in Denmark .
Taken together, we lack knowledge about whether the emerging trend of using CaM in Denmark is related to a motive of replacing prescription drugs. Previous qualitative research found that using cannabis as a substitute for prescription drugs was a motive among Danish growers of cannabis for medicinal purposes, particularly opioids . However, more knowledge is needed on user perspectives on the utility of cannabis as a substitute for prescription drugs, because user perspectives can unveil aspects of illegal drug use unseen by society at large . Also, there is a need for exploring the type of cannabis used as a substitute, as the potential negative health effects of cannabis use varies according to the subtype of cannabis used . Finally, the vast majority of studies have been conducted in the USA and Canada, and we lack studies examining potential use of CaM as substitution for prescription drug use in a European context.
The aim of the present study was to examine to what extent CaM is used as a substitute for prescription drugs in a convenience sample of Danish users of CaM, and to characterize the substitution users. Furthermore, the study aimed to examine what type of prescription drugs are substituted with CaM, what types of cannabis are used as substitution, and the perceived impact on prescription drug use. Finally, we aimed to compare perceived effects and side effects of CaM compared to prescription drugs used.
The study was based on data from the first survey on use of CaM conducted in Denmark (for more details, see ). A novel survey was developed, inspired by previous studies on users of CaM [27, 74,75,76,77,78,79]. The full survey consisted of 44 structured questions and 19 possible follow-up questions answered in a Yes/No format, multiple-choice response, or rating scales. The survey took about 15 min to complete, and was available in Danish only. Data were collected through SurveyXact. IP addresses of the respondents were not saved or available to the researchers, as the respondent’s anonymity was considered a greater issue than the possibility of repeated participation . We have previously reported on the motives for use and patterns of use from 3.021 respondents from this survey .
Sampling and recruitment
The survey was made available online to a self-selected convenience sample of users of CaM from July 14th 2018 to November 1st 2018. Inclusion criteria were being 18 years or older and being a user of CaM, either prescribed by a doctor or non-prescribed with a self-perceived medical purpose. Users of CaM who had stopped using cannabis were included in the sample and characterized as former users of CaM. Participants were recruited via online material, flyers, and posters with information about the survey, and a survey link and QR code directing to the survey. The material was disseminated on social media, through patient organizations, in doctors’ offices and hospitals, at the illegal open drug market in Denmark (Christiania), the first Cannabis Expo in Denmark, and via headshops selling cannabis-related items. Furthermore, the survey was made available through Smokeboddy (an app where users monitor potential police presence at Christiania) and was covered by the national media (The Danish Broadcasting Corporation).
The full survey included several key domains; sociodemographics, motivation for use, patterns of use, and evaluation of perceived efficacy and adverse effects. In the present study, the following domains were used for the data analyses (see description of the remaining measures in ).
Current and former users of CaM
Respondents were asked an introductory question: Do you use CaM?, and could answer either Yes/No or “I have used CaM, but I stopped”. Respondents who answered “Yes” were defined as current users, while those who indicated having past experience with the use of CaM were defined as former users, and those that answered “No” were not included in the study sample.
Users who used CaM as a substitute for prescribed drugs
Respondents were asked if they had experience with using prescription drugs to treat somatic or mental health condition(s). Those who responded positive were asked a follow-up question on whether they had ever used CaM with the purpose of replacing a prescribed drug. Those who answered affirmatively were categorized as “substitution users”, while all other respondents were categorized as “non-substitution users.”
Type of drug substituted
Respondents were asked which prescription drugs they had replaced with cannabis and were provided with six response categories: Pain-medication, Anti-depressants, Anti-psychotic, Anti-epileptic, Arthritis-medication, and an “Other” category, and could choose more than one category. Each category was followed with an open-ended question, where respondents were encouraged to write the brand of the prescribed drug.
Impact of CaM on prescription drug use
Respondents were asked to evaluate how their use of CaM affected their use of prescription drugs on a 6-point scale from ‘use of prescription drugs has increased substantially’ (1) to ‘use of prescription drugs has decreased substantially’ (5), including an option to indicate cessation of prescription drug use; ‘I have stopped using prescription drugs’ (6).
Effects and side effects
Respondents were asked to evaluate the experienced effects and side effects of CaM compared to the substituted prescription drugs on a 5-point Likert scale from ‘CaM is much more effective than prescription drugs’ (1) to ‘prescription drugs are much more effective than CaM’ (5).
Data analysis was conducted using Stata SE/15  and Nvivo 12 . Figures were produced in Excel 2016 and Word 2016. Descriptive statistics were used to describe sample characteristics, conditions treated, and patterns of use. A histogram was used to assess normality in the variable for a number of conditions. As the variables were not normally distributed, the Mann–Whitney U test  was used to assess differences in means between substitution users and non-substitution users. We coded a dummy variable, distinguishing between substitution users and non-substitution users, with substitution users coded as 1 (both former and current users of CaM were include). This variable was used as the dependent variable in the logistic regression analysis. Odds ratios (ORs) from multiple logistic regression, controlled for age, gender, and current employment, were used to estimate the strength of association between substituted prescription drug and type of cannabis used. The distribution of the qualitative responses for brands of prescription drugs was quantified in Nvivo 12.
The 52 conditions that the CaM respondents could choose from, when reporting conditions treated with CaM, were categorized as either somatic conditions (n = 36) or psychiatric conditions (n = 13), except for “chronic pain”, “sleep disturbances”, and “stress”, which were kept as independent categories (See “Appendix 2”). In order to explore CBD-oil use only, we coded a dummy variable for use of CBD-oil only (1) and use of other cannabis products (0). Of the 4.570 respondents who opened the survey, 3.140 answered all questions. Of these, 234 were excluded: 59 were under the age of 18, 115 answered on behalf of someone next of kin, seven had inconsistencies in answers, and 53 were identified as duplicates. Respondents with missing responses to the question on substitution as a motive for use of CaM (n = 65) were also excluded, leaving a final sample of 2.841.
The specific brand of prescription drugs entered in the open-ended questions was grouped together under their shared active ingredient. Non-specific entries (e.g., “strong pain killers” or “migraine medication”) were discarded. All entries for drugs that are also available over the counter (e.g., Ibuprofen or Panodil) were assumed to be obtained via prescription, given the nature of the survey questions. A different approach was taken in the “Other” category, where all entries were coded into new categories. Specific entries such as “melatonin” and “imovane” were coded as “sleep medication” together with non-specific entries, such as “sleeping pills”. The most prevalent new categories (n > 20) are reported.
Respondents consented to participate and could drop out of the survey at any time before completion. Respondents were not compensated for participating. The data used for this study were collected and stored for monitoring on secure servers, and procedures for data handling and storage were approved by the Danish Data Protection Agency. No ethics evaluation was needed under Danish law.
The majority of respondents were female (63.2%), and aged 45 years or older (64.1%) (see Table 1). The most prevalent level of education was “medium cycle higher-education” (28.7%) and “vocational secondary education” (18%). Employment status was mixed with 25.9% in full-time employment, 21.8% on disability pension, and 18.4% in reduced employment. All five regions of Denmark were represented in the study.
The most prevalent type of CaM was CBD-oil (65.1%), followed by “hash, pot or skunk” (36.4%), and THC-oil (24.5%), and oil was the most frequent form of intake (56.4%) (see Table 2). Most users had limited recreational experience (63.5%), and the vast majority were current users (91.1%), with no prescription for medical cannabis (91%). A majority of respondents used CaM in the treatment of a somatic condition (73.3%), followed by psychiatric conditions (37.1%), chronic pain (32.8%), sleep disturbances (27.9%), and stress (24.1%) (See Table 2). The most prevalent somatic condition treated with CaM was osteoarthritis (23.2%), and almost equally prevalent among the psychiatric conditions were anxiety (19.6%) and depression (19.5%).
CaM used as a substitute for prescription drugs, and substitution user characteristics
The majority (70.1%) indicated that they had experience using prescription drugs in treatment of their condition(s), of which 77.7% (n = 1.546) had used CaM with the explicit purpose of replacing a prescribed drug. Thus, substitution users made up more than half of the total sample (54.6%).
Prescription drugs substituted and impact of using CaM as a substitute
Pain medication (67.2%) was the most common type of prescription drug substituted, followed by anti-depressants (24.5%), “other” (24.1%), and arthritis medication (20.7%) (see Fig. 1). Specific brands or classes of prescription drugs were listed 1.887 times, of which 1.246 (66%) were pain medication with Tramadol (27.2%) and Morphine (15.5%) as the most common (see Table 3). In the “Other” category, 432 drugs were listed, and the most prevalent medications were “sleep medication” (16%), “ADHD medication” (13.7%), and “anxiety medication” (8.1%).
Type of prescription drug(s) substituted with CaM
Table 3 Five most prevalent classes of prescription drugs substituted with CaM (brands in parentheses)
Among the 1.546 respondents who reported using CaM as a substitute for prescription drugs, the vast majority had stopped using prescription drugs (38.1%) or reduced their use substantially (45.9%). Very few reported a substantial/slight increase in prescription drug use (0.1%) as a consequence of their use of CaM (see Fig. 2).
Effect of substitution with CaM on prescription drug (PD) use
Type of cannabis used as a substitute
Type of cannabis used varied depending on the types of prescription drugs substituted (see Fig. 3). CBD-oil was the most prevalent type of cannabis used among those who substituted arthritis medication (74.4%), pain medication (66.6%), anti-epileptics (66.4%), and anti-depressants (60.7%), but not among those who substituted anti-psychotics (42%), where “hash, pot or skunk” were the most common types used (80%). The odds of using “hash, pot or skunk” were 1.45 times higher among users who substituted anti-depressants (95% CI 1.08–1.95, p < 0.05), and 3.37 times higher among users who substituted anti-psychotics (95% CI 1.87–6.08, p < 0.001). Users who substituted pain medication were 1.72 times more likely to use THC-oil (95% CI 1.30–2.27, p < 0.001), and users who substituted arthritis medication were 1.46 times more likely to use CBD-oil (95% CI 1.08–1.98, p < 0.05).
Experienced effects and side effects
More than half (65.8%) indicated that CaM was a ‘much more effective’ treatment of their condition(s) compared to prescription drugs. A minority indicated that prescription drugs were ‘slightly more effective’ (2.2%) or ‘much more effective’ (1.2%) compared to CaM (see Fig. 4).
Effects of CaM compared to effects of prescription drugs (PD)
When comparing side effects between prescription drugs and CaM, the majority (85.5%) indicated that the side effects of prescription drugs were ‘much worse’ than the side effects of CaM, and a minority reported that the side effects of CaM were ‘slightly worse’ (1%) or ‘much worse’ (0.4%) than the side effects of prescription drugs (see Fig. 5).
Side effects of CaM compared to side effects of prescription drugs (PD)
To our knowledge, the present study is the largest study to date on self-reported use of CaM as substitution for prescription drugs in a European sample. Further, the study is the first to explore the type of cannabis used as a substitute across different types of prescription drugs, providing valuable insights into user perspectives on CaM as a substitute for prescription drugs in treating somatic and mental health conditions.
Our findings show that substitution of prescription drugs is a leading motive among users of CaM in a Danish convenience sample, and that this practice is more common among women, people with reduced working capacity due to illness, and people with chronic pain and other somatic conditions. We found that pain medication by far was the most common type of prescription drug substituted, followed by anti-depressants and arthritis medication, and that Tramadol was the most common class of pain medication that was substituted with CaM. Furthermore, the self-reported substitution effect was considerable, as the vast majority of substitution users reported either a substantial decrease in, or cessation of, prescription drug use as a consequence of their use of CaM. Across prescription drug categories, we found that CBD-oil was the most common form of cannabis used as substitution, except for people who substituted anti-psychotic medicines, where the use of ‘hash, pot or skunk’ was the most prevalent. A majority of the substitution users reported that CaM was much more effective in treating their conditions compared to the prescription drugs that they had used, and a large majority reported that the side effects from their use of prescription drugs were much worse compared to the side effects when using CaM.
Prevalence of substitution and characteristics of substitution users
Studies from Canada and the USA indicate that use of CaM as a substitute for prescription drugs is prevalent among users with legal access to cannabis [24, 26,27,28, 30, 64, 84, 85]. Our study adds to this literature by showing that substitution of prescription drugs is also a prevalent motive among users of CaM in a European sample, where the majority of substitution use takes place outside a legal medical setting. While a recent international cross-sectional survey found that substitution of prescription drugs was not significantly related to having legal access to medical cannabis , we found that users with legal access to CaM were significantly more likely to be substitution users compared to users without legal access. This difference may be partly explained by the fact that in Denmark, legal medical cannabis is only recommended for specific conditions when other treatment options have proven inadequate . Our finding that users with limited recreational experience with cannabis are just as likely to use cannabis as a substitute for prescription drugs as experienced recreational cannabis users is in line with previous research on substitution as a motive among prescription CaM users . Overall, the present study adds to the growing body of research indicating that use of cannabis as a substitute for prescription drugs is a prevalent phenomenon.
Our finding that women are more likely than men to substitute prescription drugs with CaM resembles previous studies [24, 28, 29] and indicates that there may be a more general pattern of gender differences related to the use of CaM. Of note, a cross-sectional survey of cannabis users from the USA found that female users report significantly lower frequency and quantity of cannabis use and significantly higher rate of medicinal use for anxiety, irritable bowel syndrome, nausea, anorexia, and migraines compared to men . Further, a qualitative study on legal medical cannabis use, also from the USA, found that gender may influence patterns and practices of use, as the narrative of female users included more collaboration with health care providers compared to the narrative of male users . While other studies have found that older CaM users are more likely to be substitution users , our study showed that a substitution motive of CaM was not significantly related to age. The fact that substitution users in our study were more likely to be on disability pension or in reduced employment may indicate that these people encounter treatment barriers in the healthcare system that ‘push’ them towards alternative types of treatment. One such barrier could be the cost of treatment, as the current instability in the prescription drug market with large fluctuations in price [88, 89] may further an economic substitution motive among some low-income patients. However, the use of unregulated cannabis may still be more expensive for most compared to the price of prescription drugs, as government reimbursement of medicine costs in Denmark are substantial . Furthermore, we found that CaM users who treat chronic pain were more likely to be substitution users, which may indicate insufficient treatment options for this patient group, as those suffering from non-malignant chronic pain are potentially undertreated [91, 92].
Type of prescription drug(s) substituted and the impact of substitution
Our finding that pain medications, particularly opioids, were the most common prescription drugs substituted with CaM, followed by anti-depressives and arthritis medication, corresponds with our findings on chronic pain, arthritis, and depression as the most frequent motives for use of CaM. These findings reflect findings from other survey studies; in a large international cross-sectional survey on cannabis users, Corroon et al.  found that opioids (13.6%), anxiolytics (12.7%), and antidepressants (12.7%) were the most common classes of prescription drugs substituted with cannabis, and a Canadian cross-sectional survey of medical cannabis patients found that opioid medications accounted for 35.3% of all prescription drug substitutions, followed by antidepressants (21.5%) .
The fact that Tramadol was the most common type of prescription drug substituted in our study may in part be explained by the prevalent use of Tramadol in treatment of non-malignant pain in Denmark . However, it may also be related to the decision by the Danish Medicines Agency to surveil prescription patterns of Tramadol among physicians in September 2017, following a rise in Tramadol use  and growing concern among clinicians’ regarding the abuse potential of Tramadol . It is likely that this decision reduced access to prescribed Tramadol for some patients, who subsequently turned to CaM in order to treat their pain condition. In fact, the number of Tramadol users in Denmark decreased for the first time since 2008 in 2017 , and continued to decrease from 2017 to 2018 (23% reduction in Tramadol users) . Indeed, problematizing and reducing opioid prescriptions leaves a vacuum that may motivate some patients to seek other therapies such as CaM . Interestingly, the increased use of Tramadol in Denmark earlier occurred as a consequence of another vacuum in the management of non-malignant pain caused by the problematization of nonsteroidal anti-inflammatory drugs (NSAIDs) and the discovery of serious long-term side effects of these drugs . Thus, there seems to be a “cycle of vacuums” in the treatment of non-malignant pain, underscoring the need to rethink the management of non-malignant pain in the Danish health care system , as this patient group is potentially undertreated .
Our findings on the cessation of and substantial decrease in prescription drug use show a considerable reported substitution effect related to the use of CaM, which is echoed in other studies on the reported substitution effect of CaM among patients with access to medical cannabis. In a survey of dispensary members in New England, the majority reported a decreased use of opioids (76.7%), anxiety medication (71.8%), migraine medication (66.7%) and sleep medication (65.2%) . Similarly, in a survey of American medical cannabis users with chronic pain, the majority of users reported complete cessation of opioids (72%) benzodiazepines (68%), NSAIDs (44%), gabapentanoids (74%), disease-modifying antirheumatic drugs (80%), Serotonin–Norepinephrine Reuptake Inhibitors (78%), and Selective Serotonin Reuptake Inhibitors (80%) . The link to a decrease in opioid use has also been shown over time in a small cohort study in New Mexico, comparing 37 chronic pain patients enrolled in a medical cannabis program to 29 non-enrolled chronic pain patients over the course of 21 months . Findings from this study showed clinically and statistically significant associations between medical cannabis enrollment and opioid prescription cessation and reduction, as well as improved quality of life. Thus, findings from our study add to the growing body of research indicating that from a user perspective, CaM has a substantial substitution effect for a variety of prescription drugs, most notably opioids.
Type of cannabis used as a substitute for prescription drugs
The findings that, in our sample, CBD-oil is the most prevalent type of cannabis used as a substitute for prescription drugs, and that one third of the substitution users used CBD-oil only, are in accordance with findings from a recent survey of 1.483 medicinal CBD users in the USA where CBD was used as a specific therapy for medical conditions, particularly pain and inflammatory disorders, as well as anxiety, depression, and sleep disorders . In the same study, the majority (65.3%) reported that CBD treated their condition(s) moderately or very well without the use of conventional medicine, and 30.4% reported that CBD was effective in combination with conventional medicine. Our findings are also in accordance with a recent Italian study, where the unintended legalization of CBD-based cannabis products with less than 0.6% THC was associated with a significant decrease in the sale of prescription drugs, particularly of anxiolytics, sedatives, and anti-psychotics . This is of particular public health interests, as CBD has been shown to have a better safety profile in terms of side effects and abuse potential, relative to THC [42, 98, 99]. In line with this, a recent review and meta-analysis of clinical trials found that CBD was well tolerated and had few serious side effects across medical conditions . The safety profile of CBD-based cannabis products may also be superior in terms of toxicology and abuse potential compared to some of the prescription medication that is substituted, such as opioids and benzodiazepines [49, 52, 53].
From a public health perspective, the problematic aspects of medicinal use of low THC/high CBD cannabis products are also, and maybe more, related to the fact that these products are unregulated and used without medical supervision . Indeed, use of unregulated cannabis products increases the risk of consuming hazardous contaminants, such as fungi, bacteria, pesticides or heavy metals [1, 102] or consuming a product with undesired psychoactive effects. Interestingly, a recent examination of CBD-oils available in Denmark by Department of Forensic Medicine in Odense, revealed that 38% of CBD-oils tested contained between 0.2% THC and 1.2% THC, despite being advertised as below 0.2% THC Footnote 1 . Thus, users of CBD-oil may unknowingly use products that are illegal to consume.
Our finding that users of CaM, who substituted anti-depressants or anti-psychotics, are significantly more inclined to use “hash, pot or skunk” compared to other substitution users is of particular interest to public health, as the THC content in skunk is high, and the THC content in cannabis resin (hash) and herbal cannabis has increased markedly in the last decades in Europe  and the USA [105, 106]. In Denmark, we found a threefold increase in THC concentration in seized hash from 2000 (mean: 8.3%) to 2017 (mean: 25.3%), while CBD levels remained stable (mean around 6%) . This trend is concerning, as increasing evidence suggests that exposure to high-THC and low-CBD cannabis products is associated with higher risk of cannabis-related harms, such as cannabis dependence [108,109,110], psychosis [111, 112], and cognitive impairment [99, 113], compared to low-THC and high-CBD products. The magnitude of the problem is further underlined by findings from naturalistic studies on users of smoked cannabis products, which indicate that users do not fully adjust their use to differences in THC concentration, suggesting that users of more potent products are exposed to higher levels of THC [114, 115]. Thus, it is possible that use of high THC cannabis products as a substitute for prescription drugs may exacerbate the condition that is the target of the treatment, particularly in relation to treatment of psychotic disorders.
In sum, there is considerable complexity related to the use of cannabis as a substitute for prescription drugs, as an evaluation of whether cannabis is in fact “the lesser of two evils” depends on various factors, such as the cannabinoid composition in the type of cannabis used, the dosage, and the type of prescription drug that is substituted. Recently, another “lesser of two evils”-dynamic is emerging from cannabinoid research, as it is increasingly plausible that low-THC cannabis products are less harmful compared to high-THC cannabis products, and that increased availability of low-THC cannabis products may hold a potential for harm reduction among users of high-THC cannabis products . In line with this reasoning, the unintended legalization of low THC-cannabis products in Italy, was not only associated with a significant decrease in prescription drug use, but also with a decrease in confiscations of illegal cannabis and drug-related arrests , indicating a substitution effect of introducing low THC-cannabis products on the consumption of conventional illegal cannabis products.
Experienced effects and side effects
Findings from our sample show that most substitution users find CaM more effective in managing their condition(s) compared to prescription drugs, and that an overwhelming majority found CaM to have a better side effect profile compared to the prescription drugs that they had been prescribed for their condition(s). This is in line with recent findings from Canada and the USA. In a cross-sectional survey, Canadian medical cannabis users listed, ‘relative safety of cannabis to prescription drug’, ‘fewer adverse side effects’ and ‘better symptom management’ as their top three reasons for using CaM as a substitute for prescription drugs . In a survey of medical cannabis patients in California who used cannabis as a substitute/in conjunction with opioid-based pain medication, 80% found that cannabis was more effective than opioids for pain, and 92% that the side effects of cannabis were more tolerable than opioids . Moreover, in a survey of American medical cannabis users with chronic pain, respondents listed ‘fewer side effects’ and ‘better symptom management’ as their top reasons for using medical cannabis as a substitute for prescription drugs . Lastly, a qualitative study on cannabis users in San Francisco showed similar perceptions among substitution users who found cannabis to be a safer and more effective alternative compared to prescription drugs . It is interesting that substitution users in our and several other studies rate the side effect profile of CaM higher than its effects, when comparing cannabis to prescription drugs. This suggests that substitution users may have the same “ lesser of two evils”-perspective on the medical utility of cannabis that was documented among some physicians in Israel , where cannabis becomes medicine not only on the basis of what it is in terms of effects, but on what it is not in terms of side effects when compared to prescription drugs. Considering the growth in use of CaM, it is likely that this perspective will result in an increasing number of people seeking information and advice about the effectiveness of CaM and use CaM as a substitute for prescription drugs, even in the absence of rigorous clinical trials and despite lack of legal access to medical cannabis. Future research is needed to assess effects and side effects of long-term use of CaM from longitudinal studies. Furthermore, placebo-controlled clinical efficacy trials are needed to explore the effects of cannabis beyond placebo, and current barriers to whole plant cannabis research need to be addressed .
Our study has several limitations. First, this self-selected convenience sample is limited by selection bias, as it likely weighs towards successful users of CaM, users with internet access, a familiarity with online surveys, users engaged with the topic on social media, and with the resources necessary to answer such surveys. Therefore, the survey may not be representative of the population of CaM users or substitution users . Second, the data used in the study may be subject to self-reporting biases, such as recall bias, confirmation bias, placebo effects or social desirability bias . For example, users are likely to have optimistic expectations regarding the efficacy of CaM  and may exaggerate positive effects of CaM or under-report adverse effects. Also, recall bias may be more salient for the small group of respondents who were not current users. Third, although duplicates were excluded from the analyses, we cannot rule out multiple responses from the same person, as IP-addresses were not accessible to researchers. Fourth, the cross-sectional study design lacks a temporal dimension, and we do not know if the reported cessation or reduction in prescription drug use is sustained over time. Fifth, findings on prescription drugs substituted may be skewed by the fact that “sleep medication”, “ADHD medication” and “anxiety medication” were not presented to respondents as independent categories. Sixth, the experienced effects and side effects of CaM and prescription drugs could potentially be affected by pharmacokinetic interactions between cannabis products and prescription drugs when taken simultaneously [120, 121]. Also, the reported effects and side effects were a mapping of substitution users experiences with various types of prescription drugs and different subtypes of cannabis, which likely vary in terms of effect and side effect profile.
The use of CaM as a substitute for prescription drugs is a leading motive among Danish users of CaM in our sample. Pain medication was the most prevalent prescription drug substituted with CaM, followed by antidepressants and arthritis medication. Tramadol was the most common pain medication substituted with CaM, which may be related to a change in prescription practices for Tramadol in Denmark. Across prescription drug categories, CBD-oil was the most prevalent type of cannabis used as substitution, except for anti-psychotics, where “hash, pot or skunk” were the most common types used, which is concerning due to the high levels of THC, particularly in hash and skunk. Substitution users reported substantial decrease or cessation of prescription drug use, and a greater effect and far better side effect profile of CaM compared to prescription drugs. Thus, from the perspective of substitution users, CaM may be viewed as the lesser of two evils compared to prescription drugs. More research is needed on the long-term consequences of use of CaM, including the impact from low and high THC cannabis products on specific somatic and mental health conditions.
Availability of data and materials
The datasets generated and/or analyzed during the current study are not publicly available as it is part of an ongoing PhD project.
Cannabidiol prescription in clinical practice: an audit on the first 400 patients in New Zealand
Cannabidiol (CBD) is the non-euphoriant component of cannabis. In 2017, the New Zealand Misuse of Drugs Regulations (1977) were amended, allowing doctors to prescribe CBD. Therapeutic benefit and tolerability of CBD remains unclear.
To review the changes in self-reported quality of life measurements, drug tolerability, and dose-dependent relationships in patients prescribed CBD oil for various conditions at a single institution.
Design & setting
An audit including all patients (n = 400) presenting to Cannabis Care, New Zealand, between 7 December 2017 and 7 December 2018 seeking CBD prescriptions
Indications for CBD use were recorded at baseline. Outcomes included EuroQol quality of life measures at baseline and after 3 weeks of use, patient-reported satisfaction, incidence of side effects, and patient-titrated dosage levels of CBD.
There may be analgesic and anxiolytic benefits of CBD in patients with non-cancer chronic pain and mental health conditions such as anxiety. CBD is well tolerated, making it safe to trial for non-cancer chronic pain, mental health, neurological, and cancer symptoms.
How this fits in
CBD prescription in primary care was legalised in New Zealand in 2017. Previous preclinical trials have shown CBD to have anxiolytic and anti-inflammatory properties but there remains a paucity of studies investigating its therapeutic potential. In this quantitative observational study of the first 400 patients prescribed CBD in New Zealand, CBD was well tolerated amongst patients with a wide range of conditions and symptoms. Quality-of-life benefit was experienced to a greater degree in patients living with non-cancer chronic pain and anxiety-related mental-health conditions, and to a lesser degree in patients with cancer or neurological symptoms.
With the amendment of the New Zealand Misuse of Drugs Regulations 1977 in 2017, CBD has become a legal prescription medicine. The amendment recognises the right of New Zealand doctors to prescribe CBD products that contain no more of 2% of 9-Δ-tetrahydrocannabinol (9-Δ-THC) in the product. 1
CBD and 9-Δ-THC are cannabinoids, active compounds found within the Cannabis genus of plants. 2 While 9-Δ-THC is the main psychoactive component responsible for euphoria and the ‘high’ associated with marijuana, CBD is the non-euphoriant component. 2 , 3
CBD is currently FDA-approved for the treatment of Dravet and Lennox-Gastaut syndrome, two childhood seizure disorders. 4 Randomised controlled trials (RCTs) have shown that, when CBD is added to existing anti-epileptic medication in patients with these syndromes, seizure frequency decreases. 5 , 6
However, CBD shows potential therapeutic use beyond this. Pre-clinical studies demonstrate that CBD has potential anti-inflammatory effects via inhibition of immune cell migration, which may be useful in chronic inflammatory conditions. 7
Moreover, preclinical studies have demonstrated anxiolytic effects of CBD. 3 , 8 – 10 Crippa et al found that in patients with generalised anxiety disorder given 400 mg of oral CBD, there was decreased cerebral blood flow to anxiety processing areas of the brain and a decrease in patient-reported anxiety when compared to placebo. 8 CBD in one double-blinded placebo-controlled RCT decreased symptoms of social anxiety disorder patients and fear of public speaking. 10 CBD may also reduce psychotic symptoms of schizophrenia. 11
CBD appears to be safe for patients, with a recent phase I dosage trial showing purified CBD oil is well tolerated up to doses of 6000 mg. 12 However, due to a paucity of clinical studies, prescribing guidelines are lacking.
The aim of this study was to conduct a clinical audit on the patient population referred to Cannabis Care (a primary care clinic in Auckland, New Zealand) for CBD oil. The authors explored the indications for prescribing CBD oil, patient quality of life, patient satisfaction, and self-titrated dosage levels.
The STROBE statement for reporting observational studies was followed. 13
Patients included in this audit were those who were prescribed CBD from 7 December 2017 to 7 December 2018. Patients included in this audit either were referred by their primary care provider or self-referred to the service. Patients were prescribed CBD oil (Tilray CBD100, Tilray, Nanaimo, BC, Canada) containing 100 mg CBD/mL in 25 mL bottles administered orally via a dropper. Bottles costed approximately USD300 each, which was self-funded as CBD is not on the New Zealand government-subsidised pharmaceutical schedule (PHARMAC).
Patient sex, age, and details of medical condition were recorded at first consultation. Each participant was grouped into one of four broad clinical groups based on their presenting medical symptoms: non-cancer chronic pain symptoms, neurological symptoms, mental health-related symptoms, or cancer symptoms. When a patient presented with symptoms fitting multiple categories, the clinician assigned the patient to the category fitting their primary presenting complaint.
Patients completed an EQ-5D-5L questionnaire at baseline before taking CBD, and again after at least 3 weeks of using the medicine as part of routine clinical assessment. The EQ-5D-5L is a two-part tool consisting of the EQ-5D-5L descriptive system and the EQ Visual Analogue scale (EQ-VAS). 14 The descriptive system measures five domains (mobility, self-care, usual activities, pain or discomfort, anxiety or depression) each with five levels of severity: no problems, slight problems, moderate problems, severe problems, and extreme problems. The EQ-VAS is a 20 cm vertical printed scale from 0 to 100 whereby the upper endpoint of the scale corresponds the ‘best health you can imagine’ and the lower corresponds to the ‘worst health you can imagine’. The patient rated their current overall health on this visual scale to yield a corresponding numerical score.
Patients also rated their satisfaction with their CBD use at follow-up. They rated their experience as ‘no benefit, good, very good, or excellent’ and reported any side effects. In addition, variations in patient dosage and the duration and frequency of CBD oil intake were recorded where possible.
The EQ-5D-5L data was measured on ordinal scales and hence considered as non-parametric data. The EQ-VAS scores were recorded on a continuous scale and treated as a parametric variable. Non-parametric data was presented as median (interquartile range [IQR]) and analysed for differences using the Wilcoxon rank sum test. Change in patient EQ-VAS scores was presented as mean (standard deviation [SD]) and analysed using one-way analysis of variance (ANOVA) to assess any differences between indication categories. Binary logistic regression was used to analyse potential dose-dependent responses, dose of CBD, and patient-reported benefit.
Categorical data such as the indications for CBD, patient satisfaction with CBD use, and side effects of use were presented as frequencies. A P value of ≤0.05 was taken as statistically significant. SPSS software (version 23.0) was used for statistical analysis.
A total of 400 patients presented to Cannabis Care from 7 December 2017 to 7 December 2018. Three patients did not receive a prescription based on a clinician decision that they would not benefit. Patients receiving CBD prescription consisted of 214 females (53.9%) and 183 males (46.1%), for a total of 397 individuals. The mean age of patients was 51.48 years (SD 19.1). Of those prescribed CBD, 61 patients (15.4%) fit more than one category of indication and were assigned to a group based on their primary condition.
Patient indication for CBD prescription is shown in Table 1 . The non-cancer pain symptoms group included patients with fibromyalgia, osteoarthritis, rheumatoid arthritis, neuropathic pain, chronic non-specific pain, pain due to ulcerative colitis, and migraines. Cancer-related symptoms included pain, nausea, poor appetite, emotional distress, and adverse effects of radiotherapy and/or chemotherapy treatment. Mental health symptoms included anxiety disorders, depressive disorders, post-traumatic stress disorder, and insomnia. Neurological symptoms included Parkinson’s disease, multiple sclerosis, epilepsy, autism spectrum disorder with challenging behaviour, amyotrophic lateral sclerosis, multiple system atrophy, various neuropathies, and tremors.
|Characteristic||Frequency, n||Proportion, %|
|Mean age, years (±SD)||51.48 (±19.1)||–|
|Indication for CBD prescription||Non-cancer pain symptoms||181||45.6|
|Mental health symptoms||64||16.1|
Of the 397 patients initially prescribed the CBD oil, 253 (63.7%) were followed up either through a second appointment with the clinician or by phone. In total, 250 patients (63.0%) reported their satisfaction with CBD use, with three patients (0.8%) refusing to comment. Within these 250 patients, a subset of 110 patients (27.7%) completed before and after EQ-5D-5L questionnaires; 144 patients (36.3%) did not complete follow-up assessment, with 82 patients (20.7%) lost to follow-up and 62 patients (15.6%) choosing not to take the CBD. Reasons for patients not taking the CBD included death, financial barriers preventing purchase of the oil, severe illness, participation in a clinical trial, or consumption of alternative illicit cannabis products.
Median follow up duration for patients who completed their CBD prescription was 36 days (IQR 28–65).
Outcomes of CBD treatment
Results from Wilcoxon rank sum tests for EQ-5D-5L domains found that patients experiencing non-cancer pain symptoms had a significant improvement of self-reported mobility scores (P = 0.02), ability to complete their usual activities (P = 0.007), self-reported pain (P<0.001), and self-reported anxiety or depression (P = 0.017). Patients with mental-health related symptoms experienced improvements to their ability to carry out their usual activities (P = 0.002), pain (P = 0.039), and anxiety or depression (P = 0.02). Patients with neurological symptoms experienced no statistically significant differences in any of the five domains. Patients with cancer symptoms experienced improvements in pain (P = 0.047). Complete results of EQ-5D-5L questionnaires are shown in Table 2 .
|Indication for CBD prescription||Domain of
|Baseline EQ-5D-5L scores, median (IQR)||Follow-up EQ-5D-5L scores, median (IQR)||P value|
|Non-cancer pain symptoms (n = 53)||Mobility||2.0 (1.0 to 3.0)||2.0 (1.0 to 3.0)||0.022|
|Self-care||1.0 (1.0 to 2.0)||1.0 (1.0 to 2.0)||0.046|
|Usual activities||3.0 (2.0 to 4.0)||2.0 (1.0 to 3.0)||0.007|
|Pain/discomfort||3.5 (3.0 to 4.0)||3.0 (2.0 to 3.0)|
|Anxiety/depression||2.0 (1.0 to 3.0)||2.0 (1.0 to 2.0)||0.017|
|Mental health symptoms (n = 21)||Mobility||1.0 (1.0 to 1.0)||1.0 (1.0 to 1.0)||0.577|
|Self-care||1.0 (1.0 to 1.75)||1.0 (1.0 to 1.0)||0.096|
|Usual activities||3.0 (2.0 to 3.0)||1.0 (1.0 to 2.0)||0.002|
|Pain/discomfort||2.0 (1.0 to 3.0)||1.0 (1.0 to 2.0)||0.039|
|Anxiety/depression||4.0 (3.0 to 4.0)||2.0 (1.5 to 3.0)||0.002|
|Neurological symptoms (n = 11)||Mobility||1.0 (1.0 to 3.0)||1.5 (1.0 to 2.0)||0.317|
|Self-care||1.0 (1.0 to 3.0)||1.5 (1.0 to 2.0)||0.317|
|Usual activities||3.0 (1.75 to 4.0)||2.5 (1.75 to 3.25)||0.194|
|Pain/discomfort||3.0 (1.5 to 3.5)||3.0 (1.5 to 3.0)||0.18|
|Anxiety/depression||3.0 (2.0 to 3.0)||1.5 (1.0 to 3.0)||0.194|
|Cancer symptoms (n = 24)||Mobility||1.0 (1.0 to 2.0)||1.0 (1.0 to 2.0)||0.56|
|Self-care||1.0 (1.0 to 2.0)||1.0 (1.0 to 1.0)||1|
|Usual activities||2.0 (1.0 to 2.75)||2.0 (1.0 to 3.0)||1|
|Pain/discomfort||3.0 (2.0 to 3.0)||2.0 (1.0 to 2.5)||0.047|
|Anxiety/depression||2.0 (1.0 to 3.0)||1.0 (1.0 to 2.0)||0.11|
Score of 1 = no problems, 2 = slight problems, 3= moderate problems, 4 = severe problems, 5 = extreme problems. P values are calculated from Wilcoxon rank sum tests. ‘Before’ scores taken at first consultation. ‘After’ scores taken after at least 3 weeks of cannabidiol intake.
CBD = cannabidiol. IQR = interquartile range.
Patient-reported satisfaction of CBD treatment found that 175 patients (70.0% of the 250 patients for whom there was available data, or 44.1% of the 397 patients prescribed the CBD), reported some level of satisfaction with CBD use (good, very good, or excellent). Seventy-five patients (30.0% of 250 patients, or 19.0% of 397 patients) reported no benefit from CBD use. There was no statistically significant relationship found between patient age or sex and patient-reported satisfaction.
Adverse effects such as sedation and vivid dreams were experienced by 25 out of 253 patients (9.9%). A worsening of a pre-existing condition was reported by 2 of 253 (0.8%) patients upon follow-up. Thirty-eight of followed-up patients (15.0%) reported positive side effects of CBD use, such as improved sleep or improved appetite. Side effects experienced by follow-up patients are summarised in Table 3 .
|Side effect||Frequency, n (%)|
|Improved sleep||31 (12.3)|
|Improved appetite||7 (2.8)|
|Vivid dreams||5 (2.0)|
|Emotional disturbances eg, irritable, depressed, anxious||5 (2.0)|
|Oral mucosa irritation||1 (0.4)|
Amongst those who completed the course of CBD, the dose per day ranged from 40mg/day to 300mg/day. However, dosage information was incomplete, existing for only 110 patients out of the 253 followed-up patients (43.5%). The clinician recommended dosing to at least 100 mg/day. Overall dosage between patients varied widely and was reported inconsistently by patients. Binary logistic regression analysis was conducted for the existing values and there was no significant association between dosage and patient-reported benefit from CBD (P = 0.145).
CBD treatment improved self-reported quality of life measures for patients in the non-cancer pain and mental health-related symptom groups. There was no statistically significant improvement in those with cancer or neurological symptoms. Of those prescribed CBD, 44.1% (or 70.0% of the follow-up group) reported good to excellent benefit for relatively intractable conditions; 19.0% of those prescribed CBD (or 30.0% of the follow-up group) reported no benefit. CBD is well tolerated in most patients and may be of benefit to patients with various intractable chronic conditions.
Strengths and limitations
The strength of this study is that it assesses effects of CBD on a large range of chronic medical conditions in a clinical context. Only three patients were excluded (due to extreme severity of their conditions).
There are several limitations to this present audit. There was a large loss to follow-up due to patients not attending follow-up and cost barriers. Hence, the results reported may not be fully representative of the entire patient population. Moreover, patients had to pay USD300 for 2500 mg of the CBD oil, USD150 for an initial consultation, and USD75 for follow-up. Most patients had refractory chronic pain and conditions resistant to conventional treatment uncommon in the wider population, increasing risk of selection bias. These patients are unlikely to be representative of a wider, more generalised cohort of patients. It is difficult to elucidate the effect of selection bias on these findings. The high cost barriers may augment the placebo effect of treatment, 15 resulting in an overestimation of treatment effects. However, due to many patients having resistant symptoms, CBD may conversely prove more efficacious in patients with less severe symptoms.
The follow-up period was variable, resulting in interviews with some patients who had stopped taking CBD for a period of months. This may have confounded the patient’s recollection of the effects of CBD, likely causing an underestimation of the effect. Some follow-up was completed by the clinician instead of a non-clinical author. This increased the risk of expectation bias by the clinician, likely overestimating the effect. Considering these limitations, results should be interpreted with the appropriate caution.
Comparison with existing literature
Numerous preclinical trials 9 , 10 and neuro-imaging studies 8 have demonstrated the anxiolytic effects of CBD. A recently published case-series in psychiatric patients found a benefit of CBD for anxiety and sleep, 16 which is in agreement with the above findings.
On a pharmacological level, preclinical trials suggest CBD’s analgesic action is due to its effect on certain receptors: TRPV1 and a3 GlyRs, involved in nociceptive transmission. However, human studies are still inconclusive. 17 – 19 The apparent benefit of CBD on pain reported by patients in this audit remains difficult to interpret. Current guidelines for the prescription of medicinal cannabis, including both 9-Δ-THC and CBD, recommend it as a third-line treatment for ‘ neuropathic pain, palliative and end-of-life pain, chemotherapy-induced nausea and vomiting, and spasticity due to multiple sclerosis or spinal cord injury ’. 20 However, RCTs investigating the use of CBD alone for the treatment of pain are lacking.
The ineffectiveness of the CBD oil for 75 of the 250 patients with available data (30.0%) may be due to lack of patient compliance and inadequate dosing. The expense of the pure CBD 100 mg/mL may have influenced patient attitudes towards this matter. Previous studies investigating CBD’s anxiolytic effect have shown a U-shaped dose curve with highest efficacy at 300 mg as a single-dose. 21 This audit did not find a statistically significant dose-response, likely due to missing data and the aforementioned factors regarding financial cost.
CBD’s ineffectiveness in improving self-reported health in patients in the cancer and neurological groups may be due to the high heterogeneity of the clinical presentations within these groups. Additionally, patients within these groups had more severe disease progression compared to the mental health and non-cancer pain symptom groups, which may have limited efficacy.
Overall, CBD treatment was well tolerated with mild adverse effects, most commonly related to sedation. This is consistent with the findings of a phase I clinical trial showing the main side effects of CBD were related to the gastrointestinal and central nervous system. 12 Patient-reported sleep benefits are likely related to these sedative effects. While cannabis (containing both 9-Δ-THC and CBD) has been indicated for use as an appetite stimulant in HIV-affected patients with cachexia, 22 , 23 it remains unclear if CBD alone has significant appetite stimulating effects beyond placebo. Long-term side effects were not analysed in this current audit and future study is still needed to clarify chronic effects of CBD administration. 24
Implications for research and practice
Some urgency on this topic exists due to the increasing worldwide legalisation of cannabis and its related products. A focus should be placed on confirming the anxiolytic effects of CBD in clinical conditions. Future studies should investigate the effectiveness of full spectrum CBD oil with the retention of terpenes, the essential oils found in cannabis plants. Terpenes may enhance the effects of pure CBD because of a synergistic effect known as the entourage effect.
Overall, this audit demonstrated the potential benefit of CBD in treating anxiety and pain. The present study shows that it improves quality of life for a diverse range of patients. CBD in this population has been shown to be safe and well tolerated. However, despite potential biases of patients influenced by the high treatment cost, pure CBD is not effective for all. Benefit was more pronounced in patients who had conditions with less severe disease progression (such as mental health or non-cancer chronic pain conditions). Due to lack of a control group, high drop-out rate, and an extreme patient population, these study results should be interpreted with caution. Future studies should investigate effects of long-term CBD use, which could not be analysed in this present audit.